TransCanada Corp. (NYSE: TRP) is a natural gas play with promise, but macroeconomic hurdles and a highly leverage balanced sheet make it suitable for high-risk investors only.

TransCanada is a natural gas transmission and storage company that also owns oil assets and electric power generation assets (including 19 wholly owned power plants), among other operations.

"The global oil and gas majors have been brutally wounded since energy prices peaked last July," observes resources expert Eric Roseman.

In his Commodity Trend Alert, he explains, "We believe it's safe to start accumulating these companies again. We're buying one of the largest and best-managed natural gas companies in the world – Encana (NYSE: ECA)."

The advisor notes, "Based in Calgary, Alberta, Encana is Canada's largest natural gas distribution company based on stock market capitalization and natural gas production.

"ECA produces approximately 4.4 billion cubic feet of gas equivalent per day. More than 80% is natural gas - the cleanest burning of all fossil fuels.

"One of the 'super five' integrated oil and gas companies, Royal Dutch Shell (NYSE: RDS.A) has a diversified portfolio of oil and gas assets around the globe," says international investing expert Nick Lanyi.

In High Yield International, he says, "As one of the more conservative plays on a falling dollar and a rebound in oil & gas prices, I am adding Royal Dutch Shell -- yielding of 5.8% -- to our 'Reliable Income' portfolio."

"The Amsterdam-based company's revenue is more gas-oriented than its other super-major peers; about 40% of production is natural gas.

"In addition, Shell is more focused on unconventional sources of oil and gas than most -- the company plans to derive more than 10% of its revenue from sources such as oil sands and liquefied natural gas by 2014. This coincides with Shell's long-standing reputation as an industry leader in technology and engineering.

"Oil stocks have been hinting at a rebound; as much as I think that crude oil is oversold, natural gas looks even cheaper," says Charles Payne.

The editor of WStreet Strategies explains, "Natural gas has a propensity to become oversold, and this is one of those instances." Here, the advisor reviews a pair of favorites in the sector.

"Natural gas is at April 2005 levels, the economy will drift but it's not going to roll back to levels of three years ago.

"Moreover, demand should surge as the nation's demands on the electric grid increase exponentially over the next few years. Folks, plug-in cars are going to suck up all the coal and natural gas available, and demand even more.

"In the near-term, I think that the risk/reward has shifted substantially and should trade in a range of $6.50 to $9.50, but at some point soon the bias will shift higher.

"Chesapeake Energy (NYSE: CHK) is down big time, and made news for one of the most famous executive margin calls in this current meltdown.

"Although the company's CEO, Aubrey McClendon, was forced to sell over 90% of his holdings he was putting his money where his month was.

"Mainland Resources (NASDAQ: MNLU), a small natural gas play, could be a giant in the space in a short period of time," says Charles Payne.

In his WStreet Market Commentary, he explains, " The company involved in the super exciting Haynesville shale region, which could be one of the largest domestic on shore natural gas fields ever."

"The stock has been coming on lately as more investors learn about the company's potential in the Haynesville shale region.

"Discovered in March of this year, the Haynesville field -- according to Energy and Capital -- could conservatively hold 168 trillion cubic feet of natural gas. Chesapeake Energy (NYSE: CHK) has declared Haynesville the most important find in its 19 year history.

"There was always a notion that a big find was in the space that the company currently owns (2,700 acres), but when it was first explored back in the 1950 crude oil prices were much lower and there was no technology to get to the natural gas.

"Natural gas is one of the world's most-sought-after fuels; not only is it cleaner burning and more efficient than traditional fossil fuels, it's also more efficient to transport," says Keith Fitz-Gerald.

In his always-intriguing The Money Map Reporter, he explains, "Our latest featured idea is Bermuda-based Teekay LNG Partners LP (NYSE: TGP), a liquid natural gas shipper which we consider a safe port in any economic storm."

"Many investors don't realize that liquid natural gas (LNG) comes from Indonesia, Malaysia, Qatar and other faraway places – transported by specially designed ships – and that we don't have the industrial capacity to meet modern-day demand.

"Teekay LNG Partners LP is a publicly traded master limited partnership formed by Teekay Corp. (NYSE: TK), a provider of international transportation services for petroleum products.

"The company provides marine transportation services for LNG through a fleet of ships that it owns or operates under various long-term contracts known as 'time charters.' These 15 to 20-year pacts are reached with such major energy companies.

"Rio de Janiero-based Petroleo Brasileiro S.A. (NYSE: PBR) is in the heart of the global growth story," says Daniel Frishberg, BizRadio host and editor of The MoneyMan Market Newsletter.

"In general, investors are still seeing selloffs as buying opportunities even though the majority of stocks are in a bear market. We are not sure how long this can continue.

"Our 'Crazy Investor Index' does not yet show the type of extreme fear that is typical at a bottom, so it will probably mill around in short-term rallies and selloffs until something motivates them to panic simultaneously.

"In the meantime, we prefer to buy excellent companies just as the herd decides to stampede. And while our portfolio is now slightly net short we are adding one new long position: Petroleo Brasileiro S.A., often referred to as Petrobras.

Leading advisor Jack Adamo, editor of Insiders Plus, reports that a Goldman Sachs analyst has chosen one of the stocks on his newsletter's buy list -- ConocoPhillips (NYSE: COP) -- as his top pick in the energy sector.

"There was an extremely interesting piece recently in Barron's by the oil analyst at Goldman Sachs who predicted $100 oil back in late 2004. We'd been buying energy stocks for almost a year at that point, but, although I expected oil prices to rise, I had no idea they'd go this high.

"In any case, the analyst, whose name is Arjun Murti, said he expects oil to reach $150 to $200 sometime within the next 24 months. The low end of that range is only a Middle East incident away, but the high end still seems like a reach, especially given weakening economic conditions.

"The boom in natural gas prices has been good for North American producers and their investors, both of which continue to be upbeat on the sector as share prices also keep rising," says Bill Martin.

In his exceptional BullMarket.com, he looks at SandRidge Energy (NYSE: SD), where its billionaire CEO as well as a director have continued to buy shares, despite the stock trading near "peak levels."

"Oklahoma City-based SandRidge focuses on the exploration, development, and production of oil and gas in the West Texas Overthrust, East Texas, and Mid-Continent (Oklahoma) regions.

"President, and CEO Tom Ward purchased 460,000 shares at $48.95 on May 19th/20th, which increased his already substantial holdings to nearly 36.95 million shares, or a 25.27% stake.

"It was the first purchase for Ward since he announced in March his attention to buy up to $100 million in stock on the open market this year. His only other open-market purchase came in November 2007, when he took down 4.17 million shares at $26.00 in the company's initial public offering.

"After coal, natural gas is the No. 2 source for power generation; and the largest source of gas production in the US is now unconventional reserves," explains Neil George.

In his Personal Finance newsletter, the advisor looks at two favorites plays on this trend: Chesapeake Energy (NYSE: CHK) and XTO Energy (NYSE: XTO). Here is his review.

"Unconventional reserves now account for close to 40% of all domestic gas production. In addition, with the possible exception of deepwater fields, unconventional production is the only domestic source of gas that's likely to show real growth in coming years.

"The term 'unconventional' refers to any gas field that can't be produced economically using traditional well technologies. But, using a combination of new techniques, wells drilled in unconventional fields are prolific producers. US natural gas producers remain on a 17%-plus tear in gains so far this year.

"First recommended in September 2004, Helix Energy Solutions (NYSE: HLX) is the oldest holding on our Buy List - and the biggest winner, gaining 133%," notes Richard Moroney.

Here, the editor of Upside explain, "Considering its bright profit-growth prospects, reasonable valuation, and impressive Quadrix scores, Helix remains among our very best ideas and a top pick in the oil patch."

"Helix serves energy producers worldwide, providing such contract services (36% of total revenue for the nine months ended September) as deepwater pipe-laying, well operations, robotics, and reservoir services.

"The shelf-contracting business (34%) consists of 59%-owned Cal Dive International (NYSE: DVR), a provider of dive-related and shallow-water construction services.

"The fast-growing oil and natural gas production business (30%) focuses on marginal, mature, and smaller fields - properties no longer significant or viable for large energy companies. Fueled partly by high energy prices, petroleum companies are increasingly targeting mature and small reservoirs.

"I am adding Enterprise Products Partners (NYSE: EPD) to my 'Deep-Discount' portfolio," says Nathan Slaughter, editor of Half-Priced Stocks.

The advisor explains, "Enterprise is among the nation's largest pipeline operators, owning nearly 900 miles of crude oil pipelines and 33,000 miles of natural gas, natural gas liquids (NGL), and petrochemical pipelines." Here is his review.

"Following a series of acquisitions, Enterprise is now one of the nation's largest publicly-traded energy partnerships. As a master limited partnership (MLP), the company is generally exempt from federal income taxes, provided it distributes the lion's share of its cash flows to shareholders (technically referred to as unitholders.)

"This special status allows MLPs to shell out generous payments, although these distributions typically don't qualify for the reduced 15% dividend tax rate.

"As opposed to the 'upstream' business of exploration and production, Enterprise is a 'midstream' energy player -- a sector coveted for its steady cash generation potential. Much of Enterprise's diverse revenue stream comes from pipeline charges, which are influenced more by volume flow than by volatile commodity prices.

For 25 years, Steven Halpern, editor of TheStockAdvisors.com, has surveyed the leading financial newsletter advisors asking for their favorite stocks for the coming year. This article is one of 100+ ideas in the Best Stocks for 2008 report.

"My favorite speculative idea for 2008 is China Natural Gas (NASDAQ: CHNG)," says Ian Wyatt, editor of Rising Star Stocks. "The Delaware-registered public company owns and operates natural gas-related businesses in China.

"Its core business is the distribution of compressed natural gas as a vehicular fuel to retail end users and as a natural gas utility supplying over 71,000 residential customers in Lantian County, Lintong and Baqiao Districts in the City (jurisdiction) of Xian.

"Natural gas is one of the cleanest energy sources and one of China's most abundant natural resources. For this reason, the Chinese government sees compressed natural gas (CNG)-powered vehicles as part of the solution to its national environmental woes.

"For 2007 analysts estimate earnings of 38 cents per share on revenues of $33.9 million, an increase of 80% from revenues of $18.8 million in 2006. In 2008 analysts see China Natural Gas growing its earnings to 58 cents on revenues of $55.4 million, a 63% increase from the 2007 estimate of $33.9 million.

"The big, integrated oil companies are known for their relative safety and stability, and most have been paying dividends for many years " says energy expert Elliott Gue.

In his The Energy Strategist he explains, "These have been among the most reliable stocks investors can own in the long run." Here, he looks at Chevron (NYSE: CVX), which he calls his favorite among the US independent oil companies.

"Chevron remains relatively cheap in three valuation measures: price-to-barrel of oil equivalents; price-to-earnings and price-to-cash-flow. And while its 2.7% yield doesn't exactly make Chevron an income stock, it's consistently boosted that payout over time by more than 10% annualized over the past five years.

"Chevron is also one of the only Super Oils that will show meaningful growth in production over the coming few years. Even more important, it's scheduled to start up four major projects over just the next two years that will generate significant production growth upside near term. Here's a quick rundown:

"Tahiti is a deepwater field in the Gulf of Mexico where Chevron holds a 58% stake. The field is expected to have a peak production rate of 125,000 barrels of oil per day and 70 million cubic feet of natural gas.

Through a combination of capital gains and dividend yield, the goal of The 25% Cash Machine is to generate 25% annual returns from a combination. Editor Bryan Perry is now building a new position for this portfolio: Cheniere Energy Partners (NYSE: CQP), a play on liquefied natural gas (LNG).

The advisor explains, "LNG is natural gas -- the same clean, safe energy source used to fuel our homes and industries -- that's been reduced to 1/600th its volume through a sophisticated refrigeration process. In liquid form, natural gas can be shipped long distances safely and economically in specially designed ships with insulated storage tanks.

"World demand for liquefied natural gas is expected to double by 2010. The reason demand for LNG is growing is that it is viewed as safe, flexible, reliable, and economical. One other big (perhaps the biggest) plus in the current (and growing) green climate is that LNG is environmentally acceptable.